Fig 1. The time and medium dependence of ECAO expression and activity.

(A) The kinetics of ECAO induction in E. coli K-12 (wt) cultured in M9-lactose medium supplemented with 5 mM PEA (n = 4). The 0 h time point corresponds to the time when the cells were diluted into PEA-containing culture medium. (B) The activity of ECAO is induced in E. coli K-12 (wt), but not in our ΔtynA strain, by the presence of both lactose and PEA 6 h after diluting the bacterial cultures in M9-lactose-PEA media (n = 3). (C) The H₂O₂ production of wt K-12 E. coli and ΔtynA bacteria in stationary phase in M9-lactose-PEA medium (** p < 0.01). The means ± SEMs are shown.